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formech_1372:formech_1372 [2021/08/23 01:48] – [General tips] formlabformech_1372:formech_1372 [2024/03/01 01:38] (current) – [Medium Gauge Film] formlab
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   * Small: ''500 x 500 mm''   * Small: ''500 x 500 mm''
   * Large: ''1370 x 660mm''   * Large: ''1370 x 660mm''
 +
 +=== Pre-drying ===
 +  * PMMA: 70°C 4 hours
 +
  
 [[https://formechusa.com/wp-content/uploads/Vacuum_Forming_Guide.pdf|Vacuum Forming Guide]] [[https://formechusa.com/wp-content/uploads/Vacuum_Forming_Guide.pdf|Vacuum Forming Guide]]
 ---- ----
 +
 +===== Mould tips =====
 +
 +<WRAP center round important 60%>
 +Moulds should not contain moisture or dust (!) since it could harm the vacuum pump.
 +</WRAP>
 +
 +
 +  * Can the mould be removed after forming?
 +    * {{:formech_1372:good-mould.png?200|}}\\ **Good mould**
 +    * {{:formech_1372:bad-mould-01.png?200|}}\\ **Bad mould**: even though it looks like it should work, the plastic shrinks while cooling, so vertical walls will be gripped so tight it'll be impossible to remove the mould.
 +    * {{:formech_1372:bad-mould-02.png?200|}}\\ **Very bad mould**: this is an undercut. The mould can never be removed without cutting the plastic sheet
 +  * Include draft angles:\\ {{:formech_1372:draft-angle.png?200|}}
 +  * Can the vacuum reach all pockets?
 +    * {{:formech_1372:vent-holes_01.png?200|}}\\ {{:formech_1372:vent-holes-02.png?200|}}\\ Insert vent holes
 +  * Can it withstand the pressure?
 +  * Can it withstand the heat?
 +==== Tested mould materials include: ====
 +  * **Plaster** 
 +    * <color orange>**!**</color> Apply primer first and then varnish the surface
 +  * **Wood**
 +    * <color orange>**!**</color> Vacuum or varnish the surface
 +  * **PU foam**
 +    * <color orange>**!**</color> Varnish the surface!
 +    * <color green>**+**</color> Heat resistant
 +    * <color green>**+**</color> Strong enough
 +    * <color green>**+**</color> Easy to form (manually or CNC)
 +    * <color green>**+**</color> Material is porous so vent holes in small pockets are not needed
 +    * <color red>**-**</color> Limited runs (once or twice)
 +    * <color red>**-**</color> Hard to remove mould from formed sheet without breaking it
 +  * **3D printed parts** 
 +    * <color red>**-**</color> Limited runs
 +    * Plastic deforms: infill becomes visible if not enough top layers or walls.
 +  * ...
  
 ===== Available sheet materials ===== ===== Available sheet materials =====
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 ^ Thickness ^ Size ^ Cost (per sheet) ^ ^ Thickness ^ Size ^ Cost (per sheet) ^
-| 1mm | Large - 1370 x 660mm | €13,00 +| 1mm | Large - 1370 x 660mm | €16,10 | 
-| 1mm | Small - 500 x 500mm | €3,90 +| 2mm | Large - 1370 x 660mm | €32,20 
-| 2mm | Small - 500 x 500mm | €6,63 +| 1mm | Small - 500 x 500mm | €4,20 
-| 3mm | Small - 500 x 500mm | €9,62 |+| 2mm | Small - 500 x 500mm | €7,14 
 +| 3mm | Small - 500 x 500mm | €10,36 |
  
 ---- ----
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 ^ Color      ^ Light      ^ Thickness          ^ Size         ^ Cost (per sheet)       ^ ^ Color      ^ Light      ^ Thickness          ^ Size         ^ Cost (per sheet)       ^
-| White | translucent | 3mm | large - 1370 x 660mm | €36,40 +| White | translucent | 3mm | large - 1370 x 660mm | €39,20 
-| White | translucent | 3mm | small - 500 x 500mm | €10,40 +| White | translucent | 3mm | small - 500 x 500mm | €11,20 
-| Green | transparent | 3mm | small - 500 x 500mm | €15,60 +| Green | transparent | 3mm | small - 500 x 500mm | €16,80 
-| Light blue | translucent | 3mm | large - 1370 x 660mm | €54,60 +| Light blue | translucent | 3mm | large - 1370 x 660mm | €58,80 
-| Light blue | translucent | 3mm | small - 500 x 500mm | €15,60 +| Light blue | translucent | 3mm | small - 500 x 500mm | €16,80 
-| Dark blue | transparent | 3mm | large - 1370 x 660mm | €54,60 +| Dark blue | transparent | 3mm | large - 1370 x 660mm | €58,80 
-| Dark blue | transparent | 3mm | small - 500 x 500mm | €15,60 +| Dark blue | transparent | 3mm | small - 500 x 500mm | €16,80 
-| Yellow | transparent | 3mm | small - 500 x 500mm | €15,60 +| Yellow | transparent | 3mm | small - 500 x 500mm | €16,80 
-| Cream | transparent | 3mm | large - 1370 x 660mm | €54,60 +| Cream | transparent | 3mm | large - 1370 x 660mm | €58,80 
-| Cream | transparent | 3mm | small - 500 x 500mm | €15,60 |+| Cream | transparent | 3mm | small - 500 x 500mm | €16,80 |
  
 ---- ----
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 ^ Color      ^ Surface finish       ^ Thickness          ^ Size         ^ Cost (per sheet)       ^ ^ Color      ^ Surface finish       ^ Thickness          ^ Size         ^ Cost (per sheet)       ^
-| white | matte / glossy | 1mm | 2000X1200 | €18,20 +| white | matte / glossy | 1mm | 2000X1200 | €19,63 
-| white | matte / glossy | 1,5mm | 2000X1200 | €26,80 +| white | matte / glossy | 1,5mm | 2000X1200 | €28,88 
-| white | matte / matte | 4mm | 2000X1000 | €45,30+| white | matte / matte | 4mm | 2000X1000 | €63,42
-| black | matte / matte | 1mm | 2000X1200 | €20,50 +| black | matte / matte | 1mm | 2000X1200 | €22,06 
-| black | matte / glossy | 1,5mm | 2000X1200 | €32,70 +| black | matte / glossy | 1,5mm | 2000X1200 | €35,19 
-| red | matte / matte | 1mm | 2000X1200 | €20,50 +| red | matte / matte | 1mm | 2000X1200 | €22,06 
-| red | matte / glossy | 1,5mm | 2000X1200 | €32,70 +| red | matte / glossy | 1,5mm | 2000X1200 | €35,19 
-| green | matte / matte | 1,5mm | 2000X1200 | €31,60 | +| green | matte / matte | 1,5mm | 2000X1200 | €34,03 |
-| blue | matte / glossy | 1,5mm | 2000X1200 | €32,70 |+
  
 === How much does it cost? === === How much does it cost? ===
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   * startup cost: €2: only when vacuum form machine is used   * startup cost: €2: only when vacuum form machine is used
   * plastic sheet cost: cost sheet, including VAT and transportation   * plastic sheet cost: cost sheet, including VAT and transportation
-  * material multiplier: 30%: item cost * 1,3 +  * material multiplier: item cost * 1,4 
-  * machine time cost: €per hour (€0,08333333 per minute)+  * machine time cost: €per hour (€0,08333333 per minute)
  
  
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   * Narrow heating band   * Narrow heating band
   * will crystallise if over heated   * will crystallise if over heated
- 
  
 ===== General tips ===== ===== General tips =====
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   * **Bubble moulding**: The table should be lowered. If it's in the up-position, the air can't pass the seals.   * **Bubble moulding**: The table should be lowered. If it's in the up-position, the air can't pass the seals.
  
 +
 +===== Drying sheets with the oven =====
 +
 +Use one of the ceramics oven in the metal atelier.\\
 +The control cabinet is behind the oven. \\
 +{{:formech_1372:oven_metal_atelier_01.jpg?400|}}\\
 +
 +
 +Get the key from Peter to be able to power on the oven.\\
 +To turn on the oven, insert the key and turn it to the right. Then turn the red knob to the right.\\
 +
 +==== Control panel ====
 +
 +{{:formech_1372:oven_metal_atelier_02_control_panel.jpg|}}
 +
 +  * There are 9 programs
 +  * Each program can have multiple segments
 +    * Example: segment 1: warm up to 70° in 30 min, segment 2: keep that temperature for 4 hours
 +  * Each segment has 2 values: a temperature, and a time
 +
 +
 +  - Press 'program' until it goes to program 5
 +    - Nothing is on here yet. (This might change in the future)
 +    - Press until there's an empty preset
 +    - In the future there might be a paper with an explanation of what programs do what. I could have a fixed entry on the list
 +  - Segment 1' is blinking. Use the up-down arrows to set a target temperature
 +  - Press the --> arrow to go to the time value
 +  - Set the time with the up-down arrows
 +  - When ready, press the stop / start button to start the oven
 +
 +==== Suggested program ====
 +
 +  * Segment 1: temp: 70° time: 30 min
 +  * Segment 2: temp: 70° time: 4 hours
 +  * Segment 3: temp: 0° time: 30 min
 ===== Clamping tips for high gauge sheets ===== ===== Clamping tips for high gauge sheets =====
   * Apply 80 grit strips of sand paper to the underside of the clamp frame to provide more grip on the sheet. The strips can be held in place with a good quality double sided tape, contact adhesive or preferably a silicone adhesive to take the heat.   * Apply 80 grit strips of sand paper to the underside of the clamp frame to provide more grip on the sheet. The strips can be held in place with a good quality double sided tape, contact adhesive or preferably a silicone adhesive to take the heat.
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-===== Machine settings ===== +===== Machine presets =====
-=== PMMA 3mm === +
-  * heater 75% en 80% +
-  * 230 sec heating (not any longer) +
-  * 60 sec cooling +
-  * --> Worked reasonably well +
-  * --> This is lower heat for a longer period+
  
-=== Medium Gauge Film (0,15mm) === +==== PS ==== 
-  * profile: 1mm PET (heater 85%+  * 1mm (Experimental v2
-  heatingseconds +    Power70% 
-  * vacuummanual operationstart-stop technique to avoid holes if there are large cavities+    * Heating: 45 seconds 
 +  * 2.5mm (Experimental v2) 
 +    * Power70%   
 +    * Heating85 seconds  
  
 +==== PETG ====
 +  * 2mm (OK)
 +    * Power: 70%  
 +    * Heating: 70 seconds  
 +
 +==== PMMA ====
 +  * 3mm
 +    * pre-dry: 4 hours at 70°C (between 70-80°C): no blisters
 +    * If using the window: add shims: 3 on each side.
 +    * heater 70% (and 75% at the edges)
 +    * 125 sec heating 
 +      * (without peeking in between)
 +      * This results in ±168°C: nice and flexible.
 +      * Sheet forming temperature: 150 - 175°C. At 150°C, the sheet is not very flexible yet
 +    * 60 sec cooling
 +
 +
 +==== Medium Gauge Film ====
 +  * 0,15mm
 +    * profile: 1mm PET (heater 85%)
 +    * heating: 8 seconds
 +    * vacuum: manual operation: start-stop technique to avoid holes if there are large cavities
 +
 +  * Polypropylene sheet: 1mm
 +    * No profile saved
 +    * Heaters at 50%
 +    * Heating: ±70 sec. Ready when sheet starts pulling flat. Might be ready much earlier too, but these values are the ones we used for testing. The plastic is very stretchy and blew holes in tiny cavities. So maybe better less heat. 
 ---- ----
  
 ===== Troubleshooting ===== ===== Troubleshooting =====
 +==== Preset loading gives wrong values ====
 +
 +Reason of problem: touch screen input is too fast for the slow computer (PLC)
 +
 +Fix:
 +  * **Use firm, deliberate presses with your finger** (not a stylus or fingernail).
 +  * Don’t try to be too fast.
 +
 +
 ==== Sheet pulls itself out of the clamping frame ==== ==== Sheet pulls itself out of the clamping frame ====
 //Formech//: The material is presumably not reaching the correct forming temperature, so the sheet is far stiffer than it should be, making it hard to pre-stretch the material and also as the tool comes up on the table the inflexibility of the material requires much more clamping force on the clamp frame. This is why the sheet is pulling out. If you are using the full forming aperture then you will have better clamping, providing your machine has the 8mm round silicone bead seal as shown below. //Formech//: The material is presumably not reaching the correct forming temperature, so the sheet is far stiffer than it should be, making it hard to pre-stretch the material and also as the tool comes up on the table the inflexibility of the material requires much more clamping force on the clamp frame. This is why the sheet is pulling out. If you are using the full forming aperture then you will have better clamping, providing your machine has the 8mm round silicone bead seal as shown below.
  • formech_1372/formech_1372.1629708506.txt.gz
  • Last modified: 2021/08/23 01:48
  • by formlab